采收时间对蜡蚧轮枝菌分生孢子的萌发及致病力的影响

Influence of culture age on germination and virulence of Verticillium lecanii to Trialeurodes vaporiorum

将蜡蚧轮枝菌Vp菌株在PDA培养基上23℃黑暗培养,分别于第5、15、20、25、30天后采收。将不同时间采收的分生孢子置于2％葡萄糖培养液内培养,16 h后检测其萌发率,结果表明,采收于第5天和第15天的分生孢子萌发率分别达到89.76％和94.98％,显著高于采收于第25天(30.27％)和第30天(6.12％)的孢子的萌发率;在PDA培养基培养5 d和15 d的分生孢子在相同浓度下对温室白粉虱的致病力分别达到83.40％和74.44％,显著高于培养了30 d的分生孢子的致病力(8.76％)。

Verticiiiium lecanii(Zim.)Viegas used in these experiments was strain Beijing-P, isolated from Trialeurodes vapariorum.Spores were cultured at 23℃ on PDA in total darkness and were harvested at 5 d, 15 d, 20 d, 25 d or 30 d with 2% glucose solution. The germination rate of spores and the length germ tube were examined under microscope. The results showed that the germination rate of spores harvested after 5 d and 15 d were 89.76% and 94.98% respectively, which was obviously higher than that harvested after 25 d (30.27%) and 30d (6.12%). The results of bioassay showed infection of the sopres harvested after 5 d and 15 d, reached 83.40% and 74.44% respectively, significantly different from that harvested after 30 d (8.76%). Therefore, culture age is key factor to germination and infection of spores.